Entry assembly

Abstract

A closure assembly for attachment to a vessel having an opening ring of a vessel and a closing cover cooperating with the ring and including a large diameter base end attached to the vessel and a small diameter ring end to receive a removable cover thereover. The cover end includes a plurality of spaced inwardly protruding locking lugs having a lower surface slightly inclined and the cover includes a perimeter ring flange, having a first downwardly depending skirt spaced closely adjacent and inwardly from the ring locking lugs and a second downwardly depending skirt spaced outwardly therefrom. The first skirt has outwardly protruding locking lugs spaced downwardly from the ring flange and having a slightly inclined upper surface to wedgingly mate with respective lower surfaces of the ring locking lugs. The cover has an interior surface between the first and second skirts and a D-ring seal located between the flanges on the interior surface for contacting and being compressed by the small diameter ring end.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is: 
     
       1. A leakproof closure assembly for attachment to an underground vessel which comprises an enlarged opening ring for attachment to a vessel and an enlarged closing cover for sealing against said ring and preventing water egress into said vessel; said ring comprising a tapered cylindrical ring having a large diameter planar base end adapted to be attached to said vessel and a smaller diameter planar cover end adapted to receive a cover, said cover end of said base including at least three equally spaced and inwardly protruding locking lugs having an upper surface formed substantially co-planar with said small diameter planar cover end and a lower surface spaced therefrom and inclined at a small angle to said upper surface; said cover including a perimeter ring flange, a central window, and a domed structure joining said perimeter ring flange to said window, said perimeter ring flange having a first downwardly depending skirt from said perimeter ring flange spaced closely adjacent inwardly from said locking lugs of said opening ring, and a second downwardly depending skirt, spaced outwardly from said first skirt, said first skirt including at least three equally spaced and outwardly protruding locking lugs spaced downwardly from said ring flange and having an inclined upper surface to wedgingly mate with respective said lower inclined surfaces of said locking lugs on said opening ring, said locking lugs of said cover having lower surfaces substantially parallel to said upper surface of said cover end, said cover having an interior surface between said first and second skirts substantially parallel to said upper surface of said cover end, an elastic O-ring having a D-shaped cross-section affixed on its flat to said interior surface and being contacted and compressed by said smaller diameter planar cover end of said opening ring upon substantial wedging of all said locking lugs by rotation of said cover. 
     
     
       2. The closure assembly of claim 1 wherein said opening ring and said cover are made of fiber-reinforced plastic sheet material 0.0625-0.25 inch thick. 
     
     
       3. The closure assembly of claim 1 wherein the downwardly depending length of said second skirt is about one-half the downwardly depending length of said first skirt. 
     
     
       4. The closure assembly of claim 1 wherein said base end of said opening ring has an outwardly extending flange around the perimeter of said base end. 
     
     
       5. The closure assembly of claim 1 wherein said small diameter planar cover end includes a downwardly depending skirt positioned spacedly outwardly of outer extremities of said locking lugs of said cover and having a downwardly depending length sufficient to reach the lower extremities of said locking lugs of said cover; said locking lugs of said opening ring extending inwardly from said skirt of said opening ring. 
     
     
       6. The closure assembly of claim 1 wherein said domed surface of said cover includes a pair of spaced upwardly protruding handle tabs at opposite ends of a diameter of said cover for use in turning said cover. 
     
     
       7. A corrosion-proof, leak-proof openable closure assembly for an underground containment vessel comprising an opening ring and an opening cover; said opening ring having a tapered cylindrical body with a longitudinal axis and a central axial hollow, a planar base end and a planar cover end, said base end including a flange adapted to be joined to said containment vessel, and said cover end having a planar surface and a skirt depending therefrom to form a right cylindrical surface around said longitudinal axis and at least three equally spaced locking lugs protruding inwardly from said skirt adjacent said planar surface, each said lug having an upper planar surface lying in said cover end and a lower surface spaced downwardly from said upper surface and being inclined at a small angle from said upper surface; said cover including a domed central portion surrounded by a planar circular perimeter flange, and a circular planar window substantially centrally of said domed portion; said flange including an inner skirt and an outer skirt both depending downwardly from said flange and spaced apart radially from said axis, said inner flange having at least three equally spaced locking lugs protruding outwardly from said inner skirt adjacent its bottom and spaced downwardly from said flange, each said lug having an upper surface inclined at the same angle from said flange as the lower surface of said lugs on said opening ring, said outer skirt extending downwardly about one-half of the downward length of said inner skirt. 
     
     
       8. The closure assembly of claim 7 wherein said opening ring and said cover are made of fiber-reinforced plastic sheet material about 0.125 inch thick. 
     
     
       9. The closure assembly of claim 7 wherein said locking lugs of said opening ring and said locking lugs of said cover mate with each other along their respective inclined surfaces as portions of screw threads when said cover is turned about said longitudinal axis while said opening ring is immobile. 
     
     
       10. The closure assembly of claim 7 wherein said cover includes two upwardly protruding lugs positioned respectively at opposite ends of a diameter and extending from said flange to adjacent said window and extending upwardly sufficient to provide a handhold when turning said cover to open or close said cover on said opening ring. 
     
     
       11. A closure assembly for attachment to a vessel which comprises an opening ring for attachment to a vessel and a closing cover adapted to cooperate with said ring; said ring including a tapered cylindrical ring having a large diameter planar base end adapted to be attached to said vessel and a small diameter planar cover end adapted to receive a cover, said cover end including at least three equally spaced inwardly protruding locking lugs adjacent its top, each said lug having an upper surface and a lower surface inclined at a small angle to respective said upper surfaces; said cover including a perimeter ring flange, said perimeter ring flange having a first downwardly depending skirt spaced closely adjacent and inwardly from said locking lugs of said opening ring, and a second downwardly depending skirt spaced outwardly therefrom, said first skirt including at least three equally spaced outwardly protruding locking lugs spaced downwardly from said ring flange and being adjacent its bottom, each said lug having an inclined upper surface to wedgingly mate with respective said lower inclined surfaces of said locking lugs on said opening ring, said cover having an interior surface between said first and second skirts, and sealing means located between said skirts on said interior surface for contacting said opening ring when said cover is engaged therewith, said sealing means being compressed by wedging forces of all said lugs to seal said opening ring and vessel against water intrusion. 
     
     
       12. The closure assembly of claim 11 wherein said cover includes a generally central window for providing visual inspection into said vessel without removal of said cover from said vessel. 
     
     
       13. The closure assembly of claim 11 wherein said first skirt extends downwardly generally twice as far as said second skirt. 
     
     
       14. The closure assembly of claim 11 wherein said base end of said opening ring includes an outwardly extending portion, and wherein said sealing means includes an elastic D-ring seal engaged with said outwardly extending portion of said opening ring and sealed thereagainst. 
     
     
       15. The closure of claim 11 further including two upwardly protruding handles integral with said cover for use in releasably securing said cover to said vessel. 
     
     
       16. The closure assembly of claim 11 wherein said locking lugs of said opening ring and said locking lugs of said cover mate with each other along their respective inclined surfaces as portions of screw threads when said cover is turned about a longitudinal axis while said opening ring of said vessel is immobile. 
     
     
       17. The closure assembly of claim 16 wherein said first skirt extends downwardly generally twice as far as said second skirt and said cover includes a central inspection window. 
     
     
       18. The closure assembly of claim 17 further including two upwardly protruding handles integral with said cover for use in releasably securing said cover to said vessel.